Power electronic converters are widely used in wind energy conversion system (WECS) applications. Therefore, with the increasing manufacturing capacity of multi-MW wind generators, multi-level converters, or parallel configuration of converters are becoming more attractive solutions towards DC collection from the wind generator. Among the multilevel converters, three-level full-scale neutral point diode clamped (3L-NPC) converter are using extensively for such applications in order to reduce the voltage stress on the semiconductor devices. In this article, a comparative study based on several devices used by NPC, capacitor clamped (CC) as well as Vienna rectifier has been done. Furthermore, their estimated cost comparison and complexity of control switches have been debated. By keeping in view the merits and demerits of these rectifiers, a low cost three-level active rectifier having a smaller number of active switches with a simple control scheme have been implemented. Considering a three-phase electric grid as a generated source, a 2.2KW low-cost three-level Vienna rectifier is simulated using MATLAB/Simulink. DSP (TMS320F28335) based experimental results ratify the simulated circuit with THD<5%.
Study and Implementation of a Cost-Effective 3L-Active Rectifier for DC Collection in WECS